Synthesis of Nanocrystalline VOx/MgO Aerogels and Their Application for Destructive Adsorption of CF2Cl2

Nanocrystalline VOx/MgO is extensively studied as a potential catalyst and adsorbent. In this commutation we shall report further advances to the recently developed method for synthesis of binary VOx/MgO aerogels by hydrolysis of the V and Mg alkoxides mixed together followed by gelation and supercritical drying. The suggested method of synthesis makes it possible to obtain aerogels with exceptionally high surface areas (~ 1200 m2/g) and uniform vanadium distribution. Their dehydration yields nanocrystalline VOx/MgO with nanoparticle size ca. 5 nm. The aerogel method for synthesis of the binary VOx/MgO oxide allows for obtaining the nanocrystalline materials in a wide range of vanadium concentrations. The synthesized nanocrystalline VOx/MgO oxides were used as destructive sorbents for decomposition of halocarbons. In this case, the doping of MgO aerogels with a small amount of VOx (1-2%) results in significant acceleration of the reaction causing deeper MgO transformation to MgF2 and shortening the induction period. The latter was found to shorten by as much as an order of magnitude as the vanadium concentration in the aerogel was increased. So, we developed a method for synthesis of binary VOx/MgO aerogels with high surface areas and uniform vanadium distribution that are potentially promising catalysts and destructive sorbents.